Garnet Star.

The radio astronomy observatory of the University of Cambridge. The main instrument is an Earth rotation synthesis interferometer, which consists of eight 13-metre 43-foot dishes on an east-west baseline 5 kilometres 3 miles long. This is called the Ryle Telescope after Sir Martin Ryle who founded the observatory in 1946 and was its first director. He was joint winner of the Nobel Prize for Physics in 1974 for the development of the principle of Earth rotation synthesis. In addition, there is a low-frequency deep-survey telescope of Yagi antennas operating at 151 MHz and using the same principle. The observatory has specialized in cataloguing radio sources, producing the Third, Fourth, Fifth, Sixth and Seventh Cambridge catalogues abbreviated to 3C, 4C etc. at different frequencies. These have led to the discovery of many quasars and radio galaxies. The first pulsars were detected at the MRAO in 1967. A development of the 1990s has been the construction of an optical interferometer COAST.

An institute in Surrey, south of London, which forms part of the Department of Physics and Astronomy of University College London, a constituent college of the University of London. Its work is particularly concerned with building instruments for astronomical satellites.

A telescope of unique design which operated at the Fred Lawrence Whipple Observatory on Mount Hopkins in Arizona between 1977 and 1997 as a joint venture of the Smithsonian Institution Astrophysical Observatory and the University of Arizona. It combined six individual 1.8-metre 72-inch mirrors in a circular array on an altazimuth mounting that together had the light-gathering power of a single mirror 4.5 metres 176 inches in diameter. The cost of construction was very much lower than for the single mirror equivalent at the time. Though such multi-mirror telescopes had been proposed for many years, the concept became a practical reality with the development of the computer control technology necessary to keep each mirror element pointing accurately at the same place in the sky. In 1989, taking into consideration new developments in mirror technology, the decision was made to substitute a single light-weight mirror of 6.5 metres 21 feet diameter in order to double the light-gathering power and substantially increase the field of view. The conversion was due for completion in 1998.

A group of three or more stars orbiting in a system in which they are bound together by mutual gravitational attraction. A well-known example is the four-star system, Epsilon e Lyrae.

quadrant.

Alternative spelling of the star name Mirzam.

A small southern constellation containing one second magnitude star and three of third magnitude. Its origin is obscure, but it has been attributed to Johann Bayer. See also: Table 4.

HALCA.

A proposed US/Japanese mission to obtain a sample from a small near-Earth asteroid, Nereus. A Japanese vehicle is to provide the launch in January 2002 and a miniature roving vehicle contributed by NASA will land to make measurements on the asteroid surface. The asteroid samples will be returned to Earth in January 2006 by MUSES-C via a parachute-borne capsule.